Outdoor electronic equipment enclosures and related methods

ABSTRACT

An electronic equipment enclosure for outdoor deployment includes a housing defining an interior and having an intake port, an exhaust port, an airflow path extending from the intake port to the exhaust port, and an equipment bay for receiving the electronic equipment. The equipment bay is positioned in the airflow path. The equipment enclosure further includes an intake fan for creating positive pressure within the interior of the housing and a pressure-activated damper having an open position for allowing air to exit the enclosure through the exhaust port in response to positive pressure within the interior of the housing and a closed position for preventing external air and/or water from entering the enclosure through the exhaust port when the intake fan is not operating. Other example equipment enclosures and methods are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/956,829 filed Nov. 30, 2010, which claims the benefit of U.S.Provisional Application No. 61/265,193 filed Nov. 30, 2009. The entiredisclosures of the above applications are incorporated herein byreference.

FIELD

The present disclosure relates to outdoor electronic equipmentenclosures and related methods.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

Electronic equipment enclosures are often deployed out-of-doors forhousing and protecting various types of electronic equipment such astelecommunications equipment, cable television (CATV) equipment and/ordata transmission equipment. Such equipment is sometimes referred to as“outside plant equipment.” The equipment enclosures may be locatedvirtually anywhere on Earth, where they may be exposed to inhospitableclimates having very warm, cold, wet, dry, dusty, sandy, salty and/orwindy conditions.

SUMMARY

According to one aspect of the present disclosure, an outdoor electronicequipment enclosure includes a housing defining an interior and havingan intake port, an exhaust port, an airflow path extending from theintake port to the exhaust port, and an equipment bay for receiving theelectronic equipment. The equipment bay is positioned in the airflowpath between the intake port and the exhaust port. The enclosure furtherincludes an intake fan for creating positive pressure within theinterior of the housing when the fan is operating, and apressure-activated damper having an open position for allowing air toexit the enclosure through the exhaust port in response to positivepressure within the interior of the housing and a closed position forpreventing external air and/or water from entering the enclosure throughthe exhaust port when the intake fan is not operating.

According to another aspect of the present disclosure, an outdoorelectronic equipment enclosure includes a housing defining an interiorand having an intake port, an exhaust port and an airflow path extendingfrom the intake port to the exhaust port. The enclosure further includesat least one fan for moving air through the airflow path extending fromthe intake port to the exhaust port, a first sensor for measuring an airtemperature external to the enclosure, a second sensor for measuring anair temperature within the interior of the housing, and a controlleroperatively coupled to the fan, the first sensor and the second sensor.The controller is configured to selectively operate the fan to maintaina defined temperature differential between the air temperature externalto the enclosure and the air temperature within the interior of thehousing to thereby inhibit condensation within the interior of thehousing.

According to yet another aspect of the present disclosure, a method isprovided for inhibiting condensation in an outdoor electronic equipmentenclosure. The method includes determining a maximum expected dew pointat a location of the outdoor electronic equipment enclosure, andmaintaining an air temperature within an interior of the enclosure abovethe determined maximum expected dew point to thereby avoid condensationwithin the interior of the enclosure.

Further aspects and areas of applicability will become apparent from thedescription provided herein. It should be understood that variousaspects of this disclosure may be implemented individually or incombination with one or more other aspects. It should also be understoodthat the description and specific examples in this summary are intendedfor purposes of illustration only and are not intended to limit thescope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is a block diagram of an outdoor electronic equipment enclosureaccording to one example embodiment of the present disclosure.

FIG. 2 is a block diagram of an outdoor electronic equipment enclosureaccording to another example embodiment of this disclosure.

FIG. 3 is an enlarged view of one flap of the pressure-activated dampershown in FIG. 2.

FIG. 4 is a block diagram of an outdoor electronic equipment enclosurehaving a door according to yet another example embodiment of the presentdisclosure.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a”, “an” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on”, “engaged to”,“connected to” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto”, “directly connected to” or “directly coupled to” another element orlayer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.). As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

An electronic equipment enclosure for outdoor applications according toone example embodiment of the present disclosure is illustrated in FIG.1 and indicated generally by reference number 50. As shown in FIG. 1,the enclosure 50 includes a housing 52 defining an interior 54. Thehousing 52 includes an intake port 56 and an exhaust port 58. An airflowpath extends between the intake port 56 and the exhaust port 58. Theenclosure further includes at least one fan 60 for moving air throughthe airflow path extending from the intake port 56 to the exhaust port58, a sensor 62 for measuring an air temperature external to theenclosure 50, a sensor 64 for measuring an air temperature within theinterior of the housing 52, and at least one controller 68 operativelycoupled to the fan 60 and the sensors 62, 64. The controller 68 may beconfigured to selectively operate the fan 60 to maintain a definedtemperature differential between the air temperature external to theenclosure 50 and the air temperature within the interior 54 of thehousing 52. In this manner, the controller 68 may inhibit the formationof condensation within the interior of the housing.

The defined temperature differential maintained by the controller 68 maybe a fixed temperature differential. For example, the controller 68 maybe configured to maintain the internal temperature within the interior54 of the housing 52 approximately three or five degrees Celsius abovethe external (i.e., ambient) temperature. Alternatively, the definedtemperature differential may vary depending on one or more otherparameters. For example, the controller 68 may be configured to maintainthe internal temperature at a first temperature when the externaltemperature falls within a first range (e.g., above zero degreesCelsius), and at a second temperature when the external temperaturefalls within a second range (e.g., below zero degrees Celsius).

The housing 52 may include a door, a removable panel or another suitableprovision for providing access to components within the interior 54 ofthe housing 52. Accordingly, the intake port 56 and/or the fan 60 may bepositioned over an opening in a door, a removable panel or anothersuitable portion of the housing 52, with the airflow path extendingthrough such opening, as will be further apparent from the descriptionbelow.

As shown in FIG. 1, the enclosure 50 may optionally include a heater 70.In that event, the controller 68 may be configured to control operationof the heater 70 as necessary to maintain the defined temperaturedifferential discussed above.

Under typical operating conditions, the controller 68 can reduce thetemperature within the enclosure 50 by turning on or increasing thespeed of one or more intake fans. Conversely, the controller cantypically increase the temperature within the enclosure by turning offor decreasing the speed of one or more intake fans and/or by turning onone or more heaters. Although the enclosure 50 of FIG. 1 does notinclude an air conditioning unit for providing cooling and/orcontrolling humidity, the controller 68 may still inhibit formation ofcondensation or otherwise control humidity by maintaining the definedtemperature differential. In other embodiments, one or more airconditioners can be employed for cooling and/or controlling humiditywithin the interior 54 of the housing 52.

When deployed in an outdoor environment, the enclosure 50 will house andprotect one or more pieces of outside plant equipment 72, as indicatedgenerally in FIG. 1.

Although not shown in FIG. 1, the enclosure 50 may also includehydrophobic or other filter(s) and/or damper(s) for preventing waterand/or contaminates from reaching the interior 54 of the housing 52through the intake port 56 or the exhaust port 58.

As an alternative to maintaining the defined temperature differential,the controller 68 may be configured to maintain a particular temperatureor humidity level in the enclosure 50, as further explained below. Inthis regard, the enclosure 50 may include components, such as one ormore humidity sensors, in addition to the components illustrated in FIG.1.

FIG. 2 illustrates an outdoor electronic equipment enclosure 100according to another example embodiment of the present disclosure. Asshown in FIG. 2, the enclosure 100 includes a housing 102 defining aninterior 104 and having an intake port 106, an exhaust port 108, anairflow path extending from the intake port 106 to the exhaust port 108,and an equipment bay 110 for receiving the electronic equipment. Theequipment bay 110—which may be at any desired location(s) within theinterior 104 of the enclosure 100—is positioned in the airflow pathbetween the intake port 106 and the exhaust port 108. In this manner,air passes around and/or through the electronic equipment horizontally,vertically and/or at other angles as may be necessary or desired forcontrolling the temperature of the electronic equipment.

The enclosure 100 further includes at least one intake fan 114 and atleast one pressure-activated damper 116. The intake fan 114 createspositive pressure within the interior 104 of the housing 102 when thefan 114 is operating. The pressure-activated damper 116 is movablebetween an open position for allowing air to exit the enclosure 100through the exhaust port 108 in response to positive pressure within theinterior 104 of the housing 102, and a closed position for preventingexternal air and/or water from entering the enclosure 100 through theexhaust port 108 when the intake fan 114 is not operating.

The pressure-activated damper 116 may be a passive damper, such as agravity-operated damper, or an active damper such as anelectromechanical damper. In some embodiments, including the embodimentshown in FIG. 2, the pressure-activated damper 116 is a gravity-operateddamper that automatically pivots open in response to positive pressurewithin the interior of the enclosure. The damper 116 may include severalflaps formed of plastic, rubber, metal or any other suitable material orcombination of materials. FIG. 3 illustrates one of the damper flaps inthe open position. FIG. 3 also illustrates that when the damper 116 isin the closed position, each flap is preferably oriented between aboutzero degrees (i.e., vertically) and about forty-five degrees from thevertical axis of the enclosure. It should be understood, however, thatother dampers and flap orientations may be employed, including varioustypes of active dampers, without departing from the scope of thisdisclosure.

As shown in FIG. 2, the enclosure 100 may also include a filter 112positioned in the airflow path between the intake port 106 and theequipment bay 110. In that event, positive pressure created within theinterior of the enclosure by the intake fan 114 forces filtered air outof the enclosure 100 through the exhaust port 108 and any cracks orleaks in the enclosure 100. The enclosure 100 of FIG. 2 does not includean exhaust fan associated with the exhaust port, which could createnegative pressure within the enclosure that, in turn, could drawunfiltered outdoor air into the enclosure 100 through any cracks orleaks in the enclosure. However, exhaust fans may be employed in otherembodiments without departing from the scope of this disclosure. Whenexhaust fan(s) are employed, they are preferably sized and/or operatedso that the intake fan(s) and the exhaust fan(s) collectively maintainpositive pressure (or zero pressure) within the interior of theenclosure.

The filter 112 (and the filters employed in the embodiment of FIG. 1, ifany) may be a hydrophobic and/or membrane filter for preventing solidand/or liquid contaminates from reaching the interior 104 of the housing102 via the intake port 106. For example, the hydrophobic filter 112 maybe a hydrophobic membrane filter. Examples of suitable hydrophobicmembrane filters include those available from Gore and Schrofftec. Insome embodiments, the hydrophobic filter has a pore size sufficient tofilter out, among other things, salt particles in marine environments.Alternatively, other types of filters may be employed. If a filtercapable of blocking liquids is not employed, the enclosure willpreferably including a drain for removing any water that passes throughthe filter before the water can reach the electronic equipment withinthe enclosure.

The intake fan 114 is adapted to draw outside air through the intakeport 106 and the hydrophobic filter 112, and create positive pressurewithin the interior 104 of the enclosure 100. The intake fan 114 mayhave one or more discrete speeds, and may be a variable-speed fan. Asoutdoor air is drawn through the hydrophobic filter, the hydrophobicfilter removes solids and/or liquids from the air before the air entersthe interior of the enclosure. When the damper 116 is in the openposition, air preferably exits (and does not enter) the enclosure 100through the exhaust port 108 due to the positive pressure within theinterior of the housing 102.

When the intake fan is off, the hydrophobic filter 112 prevents solidand/or liquid contaminants from entering the enclosure through theintake port 106. Further, when the intake fan is off, the flaps of thepressure-activated damper 116 close (due to the force of gravity) toprevent solid and/or liquid contaminates from entering the enclosurethrough the exhaust port 108. Accordingly, the enclosure 100 is notrequired to have a hydrophobic filter associated with the exhaust port,in addition to the hydrophobic filter 112 associated with the intakeport 106. Thus, the expense of an exhaust port hydrophobic filter can beavoided, if desired. Alternatively, the exhaust port may also beprovided with a hydrophobic or other filter, if desired, to furtherensure no solid and/or liquid contaminants enter the enclosure via theexhaust port 108.

As shown in FIG. 2, the enclosure 100 may also include, if desired, aparticle filter 118 positioned in the airflow path upstream of thehydrophobic filter 112 (i.e., air entering the intake port 106 passesthrough the particle filter 118 before reaching the hydrophobic filter112), and a heater 120, which may be an electric heater. A controller(not shown), such as an environmental control unit (ECU), may also beprovided for selectively controlling operation of the fan(s) andheater(s) as may be desired for any given application of theseteachings.

The controller may be configured to operate fan(s), heater(s) and airconditioners (if employed) as necessary to maintain the internaltemperature or humidity of the enclosure at a defined level. Forexample, the controller may be configured to operate the heater(s) asnecessary to maintain the air temperature within the enclosure above thefreezing temperature of water (i.e., zero degrees Celsius) or some otherdesired temperature (above or below zero degrees Celsius). In someembodiments, the controller is configured to shutdown the intake fan(s)and turn on one or more circulating fans within the interior of theenclosure before operating the heater. The controller may also beconfigured to maintain a positive temperature differential between theinternal temperature of the enclosure and the external (i.e., ambient)temperature outdoors, as described above, using one or more sensors (notshown in FIG. 2). Further still, the controller may be configured tomaintain the internal temperature at or above a setpoint temperature,which may be greater than the maximum expected dew point at the locationof the enclosure, as described below. At the same time, the controllermay also maintain the internal temperature of the enclosure withinoperating limits of the electronic equipment within the enclosure. Thecontroller may be a separate component, such as an environmental controlunit, or may be integrated with the intake fan(s), heater(s), sensor(s),and/or other components.

Additionally, or alternatively, the controller may be configured toinhibit condensation by controlling the relative humidity within theinterior of the enclosure. For example, the controller may be configuredto maintain the relative humidity in the enclosure below a particularsetpoint, such as 65% relative humidity. Maintaining a low relativehumidity may also reduce corrosion of equipment within the enclosure,which can occur even without condensation.

As noted above, the controller can be configured to control humidityand/or inhibit formation of condensation without employing an airconditioner. It should be understood, however, that one or more airconditioners may be employed for cooling and/or controlling humiditywithin the interior of the housing without departing from the scope ofthis disclosure.

When deployed in an outdoor environment, the enclosure 100 will houseand protect one or more pieces of outside plant equipment 72, asindicated generally in FIG. 2.

The housing 100 (as well as the housing 50 of FIG. 1) may have amonolithic or multi-part construction, possibly including one or moredoors, removable panels, or other provisions for accessing the interiorof the housing. In some embodiments, including the example embodimentshown in FIG. 4, a housing 300 may include a door 302 having an opening306 extending therethrough. The airflow path extends through dooropening 306, and the intake fan 308 is mounted to the door 302 over theopening 306 for drawing preferably filtered air into the interior of theenclosure.

Baffles may also be provided on the intake and exhaust ports (as shownin FIGS. 1-3) to force entering and/or exiting air through a convolutedpath, to reduce airspeed and protect the damper flaps (if applicable).

When the enclosures described herein are deployed outdoors, they canhouse and protect various types of electronic equipment. By employingone or more teachings herein for controlling environmental conditions(e.g., temperature, humidity and/or condensation) within the enclosure,the need to use hardened electronic equipment can be reduced oreliminated, resulting in further cost savings. Similarly, due to theenclosure designs, electronic equipment rated for near-ambienttemperatures and/or non-condensing humidity levels (e.g., non-hardenedequipment) may be advantageously deployed in the enclosures.

According to another aspect of the present disclosure, a method isprovided for inhibiting condensation in an outdoor electronic equipmentenclosure. The method includes determining a maximum expected dew pointon an external side of the enclosure, and maintaining an air temperaturewithin an interior of the enclosure above the determined maximumexpected dew point to thereby inhibit formation of condensation withinthe interior of the enclosure.

If the equipment enclosure includes a ventilating fan (such as an intakeor exhaust fan) and/or a heater, the fan and/or heater may beselectively operated to maintain the air temperature within theenclosure interior above the determined maximum expected dew point.

The method described above can be practiced with a wide variety ofoutdoor electronic equipment enclosures including, without limitation,the example outdoor equipment enclosures described above.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention. Individual elements or features ofa particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the invention, and all such modificationsare intended to be included within the scope of the invention.

1. An outdoor electronic equipment enclosure, comprising: a housingdefining an interior and having an intake port, an exhaust port, anairflow path extending from the intake port to the exhaust port, and anequipment bay for receiving electronic equipment, the equipment baypositioned in the airflow path between the intake port and the exhaustport; an intake fan for creating positive pressure within the interiorof the housing when the intake fan is operating; and apressure-activated damper having an open position for allowing air toexit the enclosure through the exhaust port in response to positivepressure within the interior of the housing and a closed position forpreventing external air and/or water from entering the enclosure throughthe exhaust port when the intake fan is not operating.
 2. The equipmentenclosure of claim 1 further comprising a filter positioned in theairflow path between the intake port and the equipment bay.
 3. Theequipment enclosure of claim 2 wherein the filter is a hydrophobicfilter.
 4. The equipment enclosure of claim 3 wherein there is noexhaust fan associated with the exhaust port.
 5. The equipment enclosureof claim 4 wherein there is no hydrophobic filter associated with theexhaust port.
 6. The equipment enclosure of claim 3 further comprising aparticle filter positioned in the airflow path upstream of thehydrophobic filter.
 7. The equipment enclosure of claim 3 wherein thehousing includes a door having an opening extending therethrough,wherein the airflow path extends through the door opening and whereinthe intake fan is mounted to the door over the door opening.
 8. Theequipment enclosure of claim 3 further comprising a controllerconfigured to selectively operate the intake fan to maintain a definedtemperature within the interior of the housing.
 9. The equipmentenclosure of claim 8 wherein the defined temperature is a function of anambient air temperature on an external side of the enclosure.
 10. Theequipment enclosure of claim 8 wherein the defined temperature is afixed temperature.
 11. The equipment enclosure of claim 3 wherein theequipment enclosure is deployed in an outdoor environment and includesat least one item of outside plant equipment positioned in the equipmentbay.
 12. The equipment enclosure of claim 3 further comprising a heater.13-23. (canceled)